This invention relates to an apparatus for providing means for re-sealing a toner hopper, which is a part of an expensive toner cartridge, used on a dry toner printer, copying machine, or facsimile machine in order that the hopper, filled with dry toner, can be shipped from one location to another, without spillage of the dry toner powder which behaves similar to a liquid.
It is customary for the manufacturer of a printer or copying machine, using dry toner, to fill the toner hopper with dry toner, and seal the top of the toner hopper with a plastic sheet, attached, and sealed on the sides of the hopper, and on each end of the hopper, just prior to assembling the toner hopper with the other components of a toner cartridge unit. When the toner cartridge is received at the using location, the seal is removed from the toner hopper section of the cartridge, and the printer or copier is ready for use, with the toner exposed to the roller feed device for making copies.
Recent developments in the dry toner imaging industry have led to the use of "throw-away" type toner cartridges, whereby the user of the copier or printer must buy a new, filled, toner cartridge from the manufacturer, when the original toner hopper in the toner cartridge is depleted of toner. This method of throw-away toner cartridges is very expensive to the user of the copier or printer as a new cartridge is required each time the toner in the toner cartridge's toner hopper is depleted. The toner is expensive enough, but to add the expense of a new cartridge, with its toner dispensing means, adds a substantial amount of cost to the replacement procedure.
It has been customary in the past to throw away these very expensive, empty toner cartridges, and replace them with new, filled, and sealed factory toner cartridges. The manufacturers seal the toner hopper components in these new toner cartridges at their manufacturing location, and there is no leakage of the toner during shipment. This type of operation, using expensive throw-away cartridges, has therefore, led to the need for a method and apparatus for re-filling, re-sealing, shipping, and re-using these toner cartridges, with the obvious savings of the cost of the new toner cartridge, in addition to the benefits of avoiding disposal and environmental problems.
No prior art is available for comparison to this invention, although the inventor is aware of several products, which have tried to solve the problem and several references are cited, which tend to outline the problem of dry toner use in these dry toner printers and copiers, and, it is obvious to a prior user of these printers and copiers that any leakage of this dry toner from the toner cartridge unit is a major cleaning problem at best, and may cause severe soiling damage to the surrounding environment, in the normal accident, as well as damage to the equipment.
One such product for re-sealing the dry toner hopper when refilling uses a plastic sheet, which slides into the slot in the toner hopper section of the toner cartridge, created when the original seal is removed.
Another product for re-sealing the dry toner in the re-filled hopper uses a plastic sheet with a magnetic coating, to try to keep the dry toner from spilling during shipment to the user. Still others try to duplicate the factory method which may require disassembly and modification of the toner hopper and thorough cleaning of the seal-grooves.
Most of the prior products, designed for this purpose of sealing the dry toner hopper for shipment, have a major problem in their design. This problem centers around the long slots along the longitudinal sides of the dry toner hopper. These slots are not sealed along this longitudinal axis, after the original seal is removed, and have irregular openings along their longitudinal axis. Now, the prior products, being of a fixed thickness, slide into the uneven slot, to fill parts of the distance of the slot, leaving minute openings along the longitudinal axis of the toner hopper, with the resulting leakage of the dry toner during shipment, causing major problems to the shipper and the receiver of the re-filled dry toner hoppers.
Another problem involves some toner hoppers that have a very narrow slot constriction that the toner seal, wider than the slot, must pull through. It is very cumbersome to seal such a toner hopper with a narrow slot constriction because the seal's width must pull through the constriction.
Another problem involves seal re-usability. Of the prior art, those seal systems that are re-usable tend to leak. However, those that do not leak are not re-usable.
Those seal systems that use a form of sticky back tape alone as the seal, have four general problems. First, these seals may tear. Second, they may stick to toner in the slot causing them to unstick therefore, not forming a perfect seal. Prevention of this unsticking requires an excessive amount of extra labor in cleaning toner from the seal-grooves. Third, these seal systems do not consistently seal well. A fourth problem involves foam-tearing. Many such seals that are leakproof tear the sealing foam in the hopper, if not from pulling the seal, whereby the sticky tape tears the foam, then the sealing foam tears from use of the common metallic insertion tool on each usage cycle. Once this foam partially tears out, the hopper will then leak, causing the problem the seal was supposed to prevent.
Another problem with prior art is that those seals that are leakproof tend to take a long time to insert, unlike a slide-seal. Those contemporary seals that are slide-seals, of prior art, tend to leak.
An invention was disclosed to solve these problems in application Ser. No. 845,722, filed Mar. 4, 1992 by this applicant. Three thin, flat, plastic or steel rectangles were made to form a seal-insert. Two were identical rectangles with a longitudinal centerline slot cut out for the purpose of allowing toner to fall through. These two rectangles sandwiched the third rectangle between them. The third rectangle had a similar slot but which was open at one end. These three rectangles were pressed firmly together and sealed together to form a one-piece seal-insert unit with an open longitudinal centerline slot. The middle rectangle's open-ended slot allowed a slide-seal to be inserted and removed. The seal-insert was intended for permanent insertion into a toner hopper. When the slide-seal, consisting of a stiff strip, slid into the slot of the middle rectangle, a seal was achieved so that toner powder could not leak out and the toner hopper could be shipped from one location to another.
The present invention is a further improvement on that disclosed seal-insert and slide-seal.